<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        /*
            媒体查询
            根据设备宽高的不同去显示对应的样式
        */
        div{
            width: 100px;
            height: 100px;
            border: 1px solid  #333;
        }
        @media (min-width:992px) and (max-width:1200px){
            div{
                width: 200px;
                background: pink;
            }
        }
        @media (min-width:768px) and (max-width:992px){
            div{
                width: 300px;
                background: blue;
            }
        }
        @media (max-width:768px){
            div{
                width: 400px;
                background: yellow;
            }
        }
            
    </style>
</head>
<body>
    <div>

    </div>
</body>
</html>